Is CVE-2021-33646 in the CISA KEV catalog?

No. CVE-2021-33646 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-33646?

CVE-2021-33646 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2021-33646?

CVE-2021-33646 has an EPSS score of 1.43% (70th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-33646?

Upgrade libtar on debian 11 to 1.2.20-8+deb12u1~deb11u1 or later. Fixes are available for 11 affected products.

CVE & CISA-KEV Catalog

CVE-2021-33646

HIGH

7.5

CVSS v3

NVD

Description

The th_read() function doesn’t free a variable t->th_buf.gnu_longname after allocating memory, which may cause a memory leak.

CWE-401Missing Release of Memory (Memory Leak)

How to fix

Remediation Available

libtarDebian

Fixed in:1.2.20-8+deb12u1~deb11u1CVE-2021-33646

Fixed in:1.2.20-8+deb12u1CVE-2021-33646

libtarRocky

Fixed in:0:1.2.20-17.el8RHSA-2023:2898

libtarRed Hat / RHEL

Fixed in:0:1.2.20-17.el8RHSA-2023:2898

libtar-debuginfoRocky

Fixed in:0:1.2.20-17.el8RHSA-2023:2898

libtar-debuginfoRed Hat / RHEL

Fixed in:0:1.2.20-17.el8RHSA-2023:2898

libtar-debugsourceRocky

Fixed in:0:1.2.20-17.el8RHSA-2023:2898

libtar-debugsourceRed Hat / RHEL

Fixed in:0:1.2.20-17.el8RHSA-2023:2898

libtarUbuntu

Fixed in:1.2.20-4ubuntu0.1~esm1USN-7398-1

Fixed in:1.2.20-7ubuntu0.1~esm1USN-7398-1

Fixed in:1.2.20-8ubuntu0.20.04.1USN-7398-1

Fixed in:1.2.20-8ubuntu0.22.04.1USN-7398-1

Fixed in:1.2.20-8.1ubuntu0.24.04.1USN-7398-1

libtar-devUbuntu

Fixed in:1.2.20-4ubuntu0.1~esm1USN-7398-1

Fixed in:1.2.20-7ubuntu0.1~esm1USN-7398-1

Fixed in:1.2.20-8ubuntu0.20.04.1USN-7398-1

Fixed in:1.2.20-8ubuntu0.22.04.1USN-7398-1

Fixed in:1.2.20-8.1ubuntu0.24.04.1USN-7398-1

libtar0Ubuntu

Fixed in:1.2.20-4ubuntu0.1~esm1USN-7398-1

Fixed in:1.2.20-7ubuntu0.1~esm1USN-7398-1

Fixed in:1.2.20-8ubuntu0.20.04.1USN-7398-1

Fixed in:1.2.20-8ubuntu0.22.04.1USN-7398-1

libtar0t64Ubuntu

Fixed in:1.2.20-8.1ubuntu0.24.04.1USN-7398-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploit Intelligence

1.43%probability of exploitation in 30 days

70thpercentile

Moderate risk: more likely to be exploited than 70% of all known CVEs.

References

Third-Party Advisory1

openeuler.org

Other references6

Related Vulnerabilities

Other CWE-401 (Missing Release of Memory (Memory Leak)) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2020-13934	High	7.5	64%	-	Fix
CVE-2016-6304	High	7.5	63%	-	Fix
CVE-2019-12265	Medium	5.3	55%	-	Fix
CVE-2001-0136	Medium	5.0	45%	-	-
CVE-2016-4232	High	7.5	36%	-	-
CVE-2001-0543	Medium	5.0	21%	-	-

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-11-03.